1. Field of the Invention
The present invention relates to a device and method for providing lane monitoring for a vehicle during driving.
2. Description of the Related Art
A lane departure warning (LDW) system provides a driver assistance function which performs a check during driving of whether the vehicle is remaining within the present lane or is about to depart from the lane. For this purpose, limit lines on the sides of the lane are detected by one or multiple cameras of the vehicle.
Published German patent documents DE 195 07 957 C1 and DE 199 37 489 B4, as well as U.S. Pat. No. 7,400,236 B2, show such lane monitoring systems having a lane departure warning function. Functions of this type are typically based on the evaluation of image sequences from a forward facing camera. U.S. Pat. No. 7,400,236 B2 proposes the use of a front camera of this type and an additional rear view camera for the purpose of detecting the side lines ahead and in back.
In some LDW systems, a time to crossing the side line marking the lane is ascertained as tLC (time to line crossing) and compared with a threshold value for the purpose of warning the driver before the actual departure from the lane. If the time drops below this threshold value, the LDW signal is output, for example to a display device in the cockpit.
However, warning signals of this type may be distracting to the driver and divert his attention during dynamic driving operations, for example if he wishes to deliberately depart from the lane.